In the reverse rolling of the Steckel mill, although two of the coiler furnaces having the heat retention function are included frontward and rearward of the rolling mills, even then, the temperatures decrease for the hot strip width end portions and front and tail end portions released from the coiler furnaces.
Then, there is a device such as in Patent Document 1 relating to a Steckel mill in the case of one rolling mill in which a heater is mounted between the coiler furnace and the rolling mill to attempt to improve the hot strip temperature. However, if the heater is a burner, heating is from the surface; the temperature increase efficiency is poor; and effects better than those of the coiler furnace cannot be expected. Also, in the case where the inductor gap is caused to approach the hot strip as much as possible to increase the efficiency as in an induction heater, even if pinch rolls are mounted, the precision of the tension detection and the tension control between the coiler furnace and the mill stand cannot be increased; and when hot strip tension loosens, the hot strip contacts the apparatus when forming a loop configuration; and it is considered that the probability of being easily damaged is high. If the inductor gap is opened in the safe direction, the heating efficiency degrades or the heating cannot be performed. Also, the locations at the rolling mill entrance and exit where the heater is mounted in the device is generally where many sensors for automatic rolling control having high priority such as strip thickness gauges, strip width gauges, radiation thermometers, hot strip detection, etc., are mounted; and there are many cases where the mounting space of the heater is not available. Also, for a multiple-mill stand configuration, there are no devices or patents describing improvement of the hot strip temperature distribution by a heater other than the coiler furnaces.